Apparatus for controlling the temperature of fuel in a motor vehicle fuel tank

Abstract

An apparatus for controlling the temperature of fuel in a motor vehicle fuel tank is described. The apparatus includes a cold valve (24) fluidly interposed between a cold fluid source (20) and a cooling portion (50) of a heat exchanger (18) and a hot valve (26) fluidly interposed between a hot fluid source (22) and a heating portion (48) of the heat exchanger (18). An air blower (28) forces air through an air duct (30) fluidly interposed between the heat exchanger (18) and an air outlet (32) to be discharged onto the vehicle fuel tank (12). A fuel temperature sensor (40) measures the temperature of the fuel in the fuel tank and generates a first input signal which is communicated to a controller (34) which then generates a control signal. The controller communicates the control signal to the cold and hot valves, whereby the cold and hot valves respond so as to maintain the difference between the first input signal and a predetermined fuel temperature profile within a predetermined range.

Claims

1. An apparatus for controlling the temperature of fuel in a motor vehicle fuel tank in accordance with a predetermined fuel temperature profile, comprising:

a heat exchanger separate from the motor vehicle having a heating portion and a cooling portion;

a cold fluid source in fluid communication with said cooling portion of said heat exchanger;

a hot fluid source in fluid communication with said heating portion of said heat exchanger;

a cold valve fluidly interposed between said cold fluid source and said cooling portion of said heat exchanger;

a hot valve fluidly interposed between said hot fluid source and said heating portion of said heat exchanger;

an air outlet adjacent to the fuel tank, said air outlet being adapted to direct a discharge air flow onto the fuel tank;

an air duct fluidly interposed between said heat exchanger and said air outlet;

an air blower in communication with said air duct, said air blower being adapted force air from said heat exchanger out through said air outlet;

a fuel temperature sensor for measuring a fuel temperature in the fuel tank and generating a first input signal; and

control means for receiving said first input signal and generating and communicating a control signal to said cold and hot valves, said hot and cold valves being responsive thereto so as to maintain the difference between said first input signal and the predetermined fuel temperature profile within a predetermined range.

2. The apparatus according to claim 1, wherein said control means includes a proportional, integral, differential compensator.

3. The apparatus according to claim 1, wherein said control means further includes a predetermined deadband to reduce cycling of said hot and cold valves.

4. The apparatus according to claim 1, wherein said hot and cold valves are variable to regulate the flow of hot and cold fluid to the heat exchanger.

5. An apparatus for controlling the temperature of fuel in a motor vehicle fuel tank in accordance with a predetermined fuel temperature profile, comprising:

a heat exchanger separate from the motor vehicle having a heating portion and a cooling portion;

a cold fluid source in fluid communication with said cooling portion of said heat exchanger;

a hot fluid source in fluid communication with said heating portion of said heat exchanger;

a cold valve opening and closing communication between said cold fluid source and said cooling portion of said heat exchanger, for producing cold fluid of variable magnitude in said cooling portion of said heat exchanger;

a hot valve opening and closing communication between said hot fluid source and said heating portion of said heat exchanger, for producing hot fluid of variable magnitude in said heating portion of said heat exchanger;

an air outlet adjacent to the fuel tank, said air outlet being adapted to direct a discharge air flow onto the fuel tank;

an air duct fluidly interposed between said heat exchanger and said air outlet;

an air blower in communication with said air duct, said air blower being adapted force air from said heat exchanger out through said air outlet;

means for sensing a fuel temperature in the fuel tank and generating an actual fuel temperature signal;

means for producing a signal representing a desired fuel temperature from the predetermined fuel temperature profile;

means for comparing said actual and desired fuel temperature signals and producing an error signal from said comparison;

feedback control means supplied with said error signal representing the difference between said desired fuel temperature and said actual fuel temperature for producing a first control signal; and

means for actuating said heat exchanger by supplying said first control signal to said cold and hot valves.

6. The apparatus according to claim 5, wherein said feedback control means includes a proportional, integral, differential compensator.

7. The apparatus according to claim 5, wherein said feedback control means further includes a predetermined deadband to reduce cycling of said hot and cold valves.

8. The apparatus according to claim 5, wherein said air blower is variable to regulate said discharge air flow rate to the fuel tank.

9. The apparatus according to claim 8, further comprising:

means for sensing a discharge air flow rate in said discharge air flow and generating an actual discharge air flow rate signal;

means for producing a signal representing a desired discharge air flow rate signal;

means for comparing said actual and desired discharge air flow rate signals and producing a third error signal from said comparison;

third feedback control means supplied with said third error signal representing the difference between said desired discharge air flow rate and said actual discharge air flow rate for producing a second control signal; and

means for actuating said air blower at variable speeds based on said second control signal.

10. An apparatus for controlling the temperature of fuel in a motor vehicle fuel tank in accordance with a predetermined fuel temperature profile, comprising:

a heat exchanger separate from the motor vehicle having a heating portion and a cooling portion;

a cold fluid source in fluid communication with said cooling portion of said heat exchanger;

a hot fluid source in fluid communication with said heating portion of said heat exchanger;

a cold valve opening and closing communication between said cold fluid source and said cooling portion of said heat exchanger, for producing cold fluid of variable magnitude in said cooling portion of said heat exchanger;

a hot valve opening and closing communication between said hot fluid source and said heating portion of said heat exchanger, for producing hot fluid of variable magnitude in said heating portion of said heat exchanger;

an air outlet adjacent to the fuel tank, said air outlet being adapted to direct a discharge air flow onto the fuel tank;

an air duct fluidly interposed between said heat exchanger and said air outlet;

an air blower in communication with said air duct, said air blower being adapted force air from said heat exchanger out through said air outlet;

means for sensing a fuel temperature in the fuel tank and generating an actual fuel temperature signal;

means for producing a signal representing a desired fuel temperature from the predetermined fuel temperature profile;

means for comparing said actual and desired fuel temperature signals and producing a first error signal from said comparison;

first feedback control means supplied with said first error signal representing the difference between said desired fuel temperature and said actual fuel temperature for producing a desired discharge air temperature signal;

means for sensing a discharge air temperature in said discharge air flow and generating an actual discharge air temperature signal;

means for comparing said actual and desired discharge air temperature signals and producing a second error signal from said comparison;

second feedback control means supplied with said second error signal representing the difference between said desired discharge air temperature and said actual discharge air temperature for producing a first control signal; and

means for actuating said heat exchanger by supplying said first control signal to said cold and hot valves.

11. The apparatus according to claim 10, wherein said first feedback control means further includes a predetermined deadband to reduce cycling of said hot and cold valves.

12. The apparatus according to claim 10, wherein said first and second feedback control means includes a proportional, integral, differential compensator.

13. The apparatus according to claim 10, wherein said air blower is variable to regulate said discharge air flow rate to the fuel tank.

14. The apparatus according to claim 13, wherein said first and second feedback control means includes a proportional, integral, differential compensator.

15. The apparatus according to claim 13, further comprising:

means for sensing a discharge air flow rate in said discharge air flow and generating an actual discharge air flow rate signal;

means for producing a signal representing a desired discharge air flow rate signal;

means for comparing said actual and desired discharge air flow rate signals and producing a third error signal from said comparison;

third feedback control means supplied with said third error signal representing the difference between said desired discharge air flow rate and said actual discharge air flow rate for producing a second control signal; and

means for actuating said air blower at variable speeds based on said second control signal.